The present invention relates to conveyor belts, particularly plastic modular conveyor belts used primarily in the food industry.
Because they do not corrode, are light weight, and are easy to clean, unlike metal conveyor belts, plastic conveyor belts are used widely, especially in conveying food products. Modular plastic conveyor belts are made up of molded plastic modular links, or belt modules, that can be arranged side by side in rows of selectable width. A series of spaced apart link ends extending from each side of the modules include aligned apertures to accommodate a pivot rod. The link ends along one end of a row of modules are interconnected with the link ends of an adjacent row. A pivot rod journaled in the aligned apertures of the side-by-side and end-to-end connected modules forms a hinge between adjacent rows. Rows of belt modules are then connected together to form an endless conveyor belt capable of articulating about a drive sprocket.
Solid or flat top modular plastic conveyor belts are often used in the food industry for meats, fish, or other products that drip or tend to drop crumbs or particles. Solid top belts typically have link ends of a shape that tapers in width from top to bottom, so that although the top of the belt can present a smooth, flat surface with very small gaps at the intercalated connection of the link ends, the link ends are spaced apart at the bottom of the belt, and gaps also open up when the belt travels around a sprocket, bending the pivot junctures. This provides the ability to clean the gaps between the link ends, which is particularly important in the food industry. Steam or hot water, which may include cleaning agents and disinfectants, can be used to clean the spaces between the link ends as the belt travels over a sprocket and changes direction. In some instances, cleaning occurs on the return portion of the belt from the reverse side. In each module, the link ends of at least one row are tapered for this purpose, with the top surface of each link end essentially being rectangular so as to fill in a rectangular gap formed by intercalated link ends of the next module. When the pivot junctures flex to an angular configuration, gaps open up between the link ends, exposing the connecting rod to some extent.
What is needed is a module design having a shape that causes the gaps between the links to change their shape when the modules pass over a sprocket yet also provides a link end geometry that is designed for optimal engagement with the teeth on the drive sprocket.
The present invention meets the above-described need by providing a module having a flat top construction with a planar deck extending to opposed link ends provided with pivot rod openings. The pivot rod openings are oval-shaped with the longitudinal axis of the oval aligned at a 45xc2x0 angle with respect to and toward the planar surface of the deck. The link ends have a proximal, planar top surface extending from the deck and forming into a distal, curved portion beginning at a position almost vertically aligned with the outer longitudinal extent of the oval pivot rod openings. The distal portion of the link ends has an inwardly angled, planar outer surface extending downwardly from the curved upper surface portion to a position substantially horizontally coplanar with a lower extent of the pivot rod openings and then to an inwardly curved surface leading to a planar bottom of the link ends. The inner portion of the link ends curves upwardly to a planar bottom surface of the deck. The deck has a concave surface between link ends which serves to receive a link end of a succeeding connected module.